组合框未显示DisplayMember

苜苜

我试图在组合框中显示问题ID，以便在文本框中重现匹配问题。然而，我没有收到所有五个问题ID的问题ID，但是有问题ID的问题：
WCInterface.ucQuestions  问题WCInterface.ucQuestions  问题
我的代码：
  A# ~. ?2 R  J) N  P% ]- ~Private loaded As Boolean = FalsePrivate Sub ucQuestions_Load(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles MyBase.Load    cmbQuestion.DisplayMember = "Question_ID"    cmbQuestion.ValueMember = "Question_ID"    cmbQuestion.DataSource = retrieveQuestions() 'when form loads    loaded = TrueEnd SubPrivate Sub cmbQuestion_SelectedIndexChanged(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles cmbQuestion.SelectedIndexChanged    If (loaded) Then        cmbQuestion.DisplayMember = "Question_ID"        cmbQuestion.ValueMember = "Question_ID"        cmbQuestion.DataSource = Nothing 'Resets data source        cmbQuestion.DataSource = retrieveQuestions() 'when form loads    End IfEnd SubPublic Function retrieveQuestions() As List(Of Question)    Dim typeList As New List(Of Question)    Dim Str As String = "SELECT Question_ID,Question_Text FROM Question"    Try        Using conn As New SqlClient.SqlConnection(DBConnection)            conn.Open()          Using cmdQuery As New SqlClient.SqlCommand(Str,conn)                Using drResult As SqlClient.SqlDataReader = cmdQuery.ExecuteReader()                  While drResult.Read                        typeList.Add(New Question(drResult("Question_ID"),drResult("Question_Text")))                    End While                End Using 'Automatically closes connection            End Using        End Using    Catch ex As Exception        MsgBox("Question List Exception: " & ex.Message & vbNewLine & Str)    End Try    Return typeListEnd Function感谢您提出如何显示问题ID谢谢你的任何建议
2 j$ A1 s3 [& J) B+ ?- e% u$ R                                                               
    解决方案: